The Invertebrate Fauna of the Uitenliage Scries. 69 



more equilateral and more coarsely ornamented than P. projectus, 

 and it has been shown, moreover, by Hennig * that Nilsson's 

 unsatisfactory figure is misleading; this shell really has relatively 

 strong ribs with linear interspaces, increasing by division and 

 insertion and not diverging from the middle line in the manner 

 represented by Nilsson. The delicate transverse striae which cross 

 the radial ornaments are scarcely comparable with the notching 

 of the "ribs" shown by P. projectus. The shell from the Gosau 

 beds described by Zittel under the name P. virgatus^ is almost 

 equilateral, and is much higher in outline than P. projectus. 



The shell from the Cretaceous of the east end of Maud Island 

 (Queen Charlotte Islands), ascribed to Camptonectes curvatus Geinitz 

 by "Whiteaves,! is somewhat similar to P. projectus, to judge from the 

 figure of a right valve, but it is more equilateral in form. 



A Pecten from the Neocornian in German East Africa was 

 described by G. Miiller under the name P. striato-punctatus, but 

 the specimen figured is so preserved that a comparison with P. 

 projectus is difficult, although it appears to differ from this in being 

 more equilateral. 



Pecten (Camptonectes} pueyrrydoiiensis Stanton,[| from the Bel- 

 grano beds (Lower Cretaceous) of Patagonia is another shell of 

 similar type, but differs at least in the more equilateral form of the 

 right valve. 



Pecten kameruncnsis von Koenen,* from Lower Cretaceous strata 

 in the Cameroons, differs from P. projectus by the more equilateral 

 form and the rather coarser ornamentation, with stronger lateral rib- 

 development. Von Koenen describes how the furrows appear here 

 and there divided by swellings into little grooves, but says that this 

 stands in connection with the crossing of lines of growth a relation 

 not to be observed in the minute ornamentation of P. projectus. 



SUB-GENUS CHLAMYS J. F. Bolten. 



PECTEN (CHLAMYS) cf. SUBACUTUS Lamarck. 



Plate II., figs. 6, 6a. 



Cf. 1819. Pecten subacutus J. B. de Lamarck, Hist. Nat. des Anim. 

 sans Vert., vol. vi., p. 181. 



* Hennig (1), p. 41, pi. 2, figs. 28, 33. f Zittel (2), p. 109, pi. xvii., fig. 8. 



I Whiteaves (3), p. 242, pi. 32, fig. 4. G. Miiller (1), p. 550, Taf. 24, fig. 7. 



1 1 Stanton (3), p. 12, pi. iv., fig. 1. 



II von Koenen (1), p. 20, Taf. iii., figs. 14, 15. 



